I found a multi-million-dollar scam apps that have no functionality, that have mislead metadata, icons, screenshots, app previews, that are promoted with mislead advertising, and that force the user (very often children) into 1-3 week subscriptions, and can charge $30 a week. These apps have totaled millions of downloads and millions of dollars in revenue per month and have the same scam method to scam users. Apps released by these people violate a lot of guidelines with the only purpose of stealing users' money.
It's very important that some apps become unavailable after a while, but I think they are removed from sale by the developer themselves. They do this so that people can't complain about the developer. But they will still get money for subscriptions in that case. It also reduces the chance of them being removed by Apple's review team. Why would I think that? Today I noticed that one app has disappeared from the AppStore, but I have the app installed. And I was still able to subscribe to the app even though it was no longer available in the AppStore.
Here is the list of apps I found, but I'm sure there are many more and I'll keep looking for them.
Appstore: 28**.03 Update!!!** https://apps.apple.com/us/app/gorilla-tag-melon-playground/id6478210133
https://apps.apple.com/us/app/ben-10-mods-melon-playground/id6478868031
https://apps.apple.com/us/app/mermaid-mods-for-minecraft-pe/id6469542384
https://apps.apple.com/us/app/catnap-mods-melon-playground/id6478156502
https://apps.apple.com/us/app/caller-id-phone-number-lookup/id6470927739
https://apps.apple.com/us/app/nextbots-mods-for-gmod/id6447346950
https://apps.apple.com/us/app/aphmau-addons-for-minecraft/id6477530154
https://apps.apple.com/us/app/mods-maps-for-baldurs-gate-3/id6476093585
25.03 Update!!! https://apps.apple.com/us/app/mods-skins-melon-playground/id6476144394
https://apps.apple.com/us/app/poppy-mods-melon-playground/id6475626405
https://apps.apple.com/us/app/toca-mods-skins-all-unlocked/id6452432738
https://apps.apple.com/us/app/digital-circus-mods-for-gacha/id6478052261
https://apps.apple.com/us/app/digital-circus-mods-for-gacha/id6478052261
https://apps.apple.com/us/app/nextbots-mods-melon-sandbox/id6476611850
https://apps.apple.com/us/app/mods-plugins-for-theotown/id6468099905
https://apps.apple.com/us/app/mermaid-mods-skins-for-toca/id6474420461
https://apps.apple.com/us/app/mods-euro-truck-simulator-2/id6477771692
https://apps.apple.com/us/app/mods-for-toca-create-stories/id6477318110
https://apps.apple.com/us/app/mods-for-melon-playground-pro/id6478051272